Attachment Inmarsat partial pet

This document pretains to SAT-ASG-20010302-00017 for Assignment on a Satellite Space Stations filing.

IBFS_SATASG2001030200017_935324

                                     Before the
                   FEDERAL COMMUNICATIONS COMMISSION
                                                                         COPY      RECEIVED
                              Washington, D.C. 20554
                                                                                      APR 1 8 2001
In the Matter of                             )                                  FEDERAL COMMUNICATIONS COMMISSiSN
                                             )                                       OrMCE oF TwE skeaEmry
Motient Services, Inc.                       ) File No
                                             )
and                                          %                     23 ‘f’&‘i’ cael

Mobile Satellite Ventures Subsidiary LLC     )                           9
                                             )                     APR    3 2
Application for Assignment of Licenses and   )
For Authority to Launch and Operate a        )               a
Next—Generation Mobile Satellite Service     )               —
System                                       )




 PARTIAL PETITION TO DENY OF INMARSAT VENTURES PLC




                                                   Kelly Cameron
                                                   Robert L. Galbreath
                                                   Powell Goldstein Frazer
                                                     & Murphy LLP
                                                   1001 Pennsylvania Ave., N.W.
                                                   Sixth Floor
                                                   Washington, D.C. 20004
                                                   (202) 347—0066

                                                   Its Attorneys
April 18, 2001


                                         Summary



        The Commission must reject that portion of the application filed by Motient

Services, Inc., and Mobile Satellite Ventures Subsidiary LLC that seeks effectively to

convert the existing Mobile Satellite Service L—Band allocation to another terrestrial

mobile service.

       First, technology and spectrum already exist that would allow Motient to provide

dual band/satellite and terrestrial service, if Motient believes that such a combined

service is crucial to its business. Motient has offered no reason why it cannot take

advantage of the existing regulatory scheme, but instead must provide both terrestrial and

satellite services in the same band.

       Second, Motient claims that its proposed dual service is "consistent with" the

Commission‘s current L—Band regulations and policy. This is patently wrong. Nothing

in the L—Band allocation or service rules proceedings, much less in any of Motient‘s

existing licenses, supports the notion that the L—Band may now be used for any service

other than MSS.

       Third, sensing the weakness of its legal claim, Motient seeks a waiver of the

Commission‘s rules to allow it to provide terrestrial L—Band service. This request must

be rejected outright. As Motient itself has stated repeatedly, the L—Band already is

extremely crowded by satellite service providers. Among the services provided in the

band are aeronautical and maritime safety services. The Commission must not grant any

new service proposal that could jeopardize these services. As demonstrated herein, and

contrary to Motient‘s limited technical evidence, the proposed terrestrial L—Band service


will indeed interfere with other L—Band satellite services unless the terrestrial service is

so limited in scope as to make it economically useless to Motient.

       Inmarsat supports efforts to improve the efficiency of MSS services. However,

despite Motient‘s claim to the contrary, the introduction of a new terrestrial allocation to

the L—Band will have no such effect. Instead, Motient‘s proposed service will block

spectrum reuse and cause unacceptable interference into co—channel and adjacent channel

satellite operations. For these reasons, Motient‘s application must be denied.




                                              d


                                         TABLE OF CONTENTS

                                                                                                                 Page

im e 1

feloCOc e Hi

1.    Motient‘s Dual—Service L—Band Proposal Is Unnecessary........................ 3

IL.   Motient‘s Dual—Service L—Band Proposal Is Inconsistent
      With Current FCC Rules and POlicle§...........2.........2..2..22k66k 62e k k26 k66 0+4

T.    No Good Cause Exists For Grant Of Motient‘s Waiver Request............... 6

      A.         Motient‘s Proposal Would Jeopardize Critical L—Band
                 SafetY SETVIC@S.........2.22..22222220266 666066 6+ es e 66e es es e se e es e e e e e e e 6k k0 k. 6

      B.    —_   Authorization of Terrestrial Mobile Services Would
                 Harm Existing and Future L—Band Satellite Operations................. 7

                 1.        Terrestrial Operations Would Significantly Damage
                           Co—Channel Satellite Frequency Reuse Capacity................ 7

                 2.        Motient‘s Proposed Terrestrial Operations Will
                           Adversely Affect Sensitive Receivers Operating
                           In Adjacent Frequency Bands..................222..22.2.......... 9

                 3.        The Proposed Terrestrial Use Will Reduce The
                           Amount Of Spectrum Available for MSS Use................. 10

      C.         Motient‘s Proposal Would Allow the Terrestrial Tail
                 To Wag The Satellite DOQ&:...........2..2..2220226e k6¥ rerrererkkr e k kk..} 11

IV.   COMCIUSIOM............2222.22222222222k622ere i6 66e ker k is 6 se e e es e e e reree se e e rer e e e .k e.. 12

ATTACHMENT 1




                                                          111


                                             Before the
                   FEDERAL COMMUNICATIONS COMMISSION
                                    Washington, D.C. 20554


In the Matter of                                      )
                                                      )
Motient Services, Inc.                                ) File No. SAT—ASG—20010302—00017
                                                      )
and                                                   )
                                                      )
Mobile Satellite Ventures Subsidiary LLC              )
                                                      )
Application for Assignment of Licenses and            )
For Authority to Launch and Operate a                 )
Next—Generation Mobile Satellite Service              )
System                                                )




       PARTIAL PETITION TO DENY OF INMARSAT VENTURES PLC

         Inmarsat Ventures plc ("Inmarsat"), by counsel and pursuant to Section 25.154

of the Commission‘s rules, hereby submits its partial petition to deny the above—

captioned applications‘ of Motient Services, Inc. ("Motient‘") and Mobile Satellite

Ventures Subsidiary LLC ("MSV Sub")(hereafter collectively referred to as

"Motient")." The Commission must reject Motient‘s request effectively to convert

the existing MSS L—Band allocation to another terrestrial mobile service.

         In the captioned applications, Motient and MSV Sub propose to (i) assign

Motient‘s licenses and pending applications to MSV Sub;" (ii) modify Motient‘s

license to permit MSV Sub to operate using certain Canadian—licensed facilities; and



* See "International Bureau Sets Deadlines Concerning Motient/TMI Assignment and Transfer of
Control Applications, and Motient‘s Request for Second Generation Satellite/Terrestrial Base Satation
System," Public Notice Report No. SAT—00066, released March 19, 2001.
2 According to Motient, MSV Sub will be 32.8% owned by Motient. TMI Communications and
Company LP ("TMI") will hold another 27.2% interest. The remaining 40% of the company will be
held by three separate investment funds.
8 By separate applications, TMI also proposes to assign its facilities licenses to MSV Sub. See File
Nos. SES—ASG—20010116—00099; SES—MOD—20010116—00097; SES—MOD—20010116—00098; Report
No. SES—000357 (January 31. 2001).


(iii) construct and operate a next—generation Mobile Satellite Service ("MSS")

system. As part of its next generation service, Motient proposes to employ fill—in base

stations to provide co—channel ter;éstfial mobile service in areas where the satellite

signal is attenuated by terrain or morphological features, and to provide in—building

coverage.* Motient claims that the proposed operation of terrestrial base stations in

the MSS L—Band is consistent with existing rules." To the extent the Commission

determines that this is not the case, however, Motient seeks a waiver of those rules "in

light of the public interest benefits that would be provided by the addition of base

stations and the absence of any interference to other users from their operation.‘""

          Inmarsat supports Motient‘s applications for assignment of its earth and space

station licenses and Section 214 authority to MSV Sub LLC, as well as its application

to launch and operate a next generation Mobile Sétellite Service system. However,

Inmarsat strongly opposes Motient‘s effort to introduce terrestrial L—Band service.

Consistent with the FCC‘s rules, Motient can use existing technology to provide

terrestrial/satellite service on a dual—band basis, using terrestrial and satellite bands.

Motient‘s proposal to provide both servicés within the L—Band would violate current

FCC rules,‘ and would fly directly in the face of the Commission‘s long—standing

efforts to accommodate international L—Band MSS. Furthermore, a waiver of the

Commission‘s rules would not serve the public interest. Motient‘s proposed

terrestrial service would severely burden other L—Band satellite operators and their

customers, including those who provide critical safety—related services, by placing

intolerable demands on the available spectrum as well as causing harmful co—channel


* Application at 8.
° Id. at 9, 15.
° Id. at 15. Motient does not identify the specific rules it seeks to have waived.
‘ These rules include, at the least, Sections 2.106 (Table of Allocations), 25.201 (definition of mobile
satellite service) and 25.202(a)&(b)(satellite service frequencies). Of course, Motient is most familiar


and adjacent channel interference. At best, the requested action would cause

substantial hardship to Inmarsat and other MSS operators. At worst, it could make the

provision of MSS — particularly critically important safety services — impossible.

          Thus, for the reasons set forth below, Inmarsat urges the Commission to deny

that portion of Motient‘s application relating to its proposed L—Band terrestrial

service."




I.       Motient‘s Dual—Service L—Band Proposal Is Unnecessary.

         As is evident throughout Motient‘s application, the terrestrial component of its

proposed service is far from a simple "ancillary" fill—in similar to an AM Subcarrier

or VBI transmission application as Motient claims." Rather, it is a major component

of a new hybrid service specifically designed for \-Videspread use. * Indeed, the scope

of terrestrial service Motient describes would far exceed its currently—licensed MSS

service. The Commission must bear this in mind when considering Motient‘s

application.

         As an initial matter, the Commissién should reject Motient‘s apparent

assumption that it can only provide the terrestrial fill—in service that it now regards as

essential to its business plan in L—Band MSS spectrum. It is simply untrue that

Motient (or any service provider) must use the same spectrum allocation in order to

provide the type of complementary services Motient proposes. Indeed, as its own

application notes, Motient already provides a dual terrestrial/satellite service


with the characteristics of the service it wishes to offer and, therefore, Motient must identify the rules
the Commission would need to waive.
° Inmarsat understands that the Commission has not yet formally accepted for filing Motient‘s waiver
request and L—Band terrestrial service proposal. In the event the Commission does so in the future,
Inmarsat reserves the right to submit supplemental comments at that time.
° Application at footnote 10.
‘° 1d. at 6 (provide improved coverage in urban areas); /4. at 13 (plan for marketing to millions of
consumers in both rural and urban areas). The application of TMI for transfer of its licenses to MSV
Sub, attached to Motient‘s Application as Appendix D, is equally explicit.


employing multiple spectrum bands.""             In fact, terrestrial mobile service providers

offer a range of handsets that operate in multiple frequency bands and on multiple

analog and digital standards in order to overcome incompatibilities among spectrum

allocations and technical specifications. Further, several MSS providers have already

developed precisely the type of hybrid terrestrial—satellite sérvice Motient seeks to

offer, including Globalstar, ACeS, and Thuraya. These services use terrestrial

allocations for terrestrial services and satellite allocations for satellite services.

Moreover, the Commission is currently considering rules for software—defined radios,

which could make such hybrid services even easier to provide.""

         Of course, Motient is free to provide terrestrial service pursuant to the rules

that govern such services. Given the technologies and wireless allocations already

available, however, Motient fails to offer any reason why it cannot take advantage of

these resources, but instead must provide terrestrial service within the L—Band.




IL.      Motient‘s Dual—Service L—Band Proposal Is Inconsistent With Current
         FCC Rules and Policies.       —

         Contrary to Motient‘s claim, there is nothing in the history of the domestic L—

Band MSS allocation process, the development of the MSS service rules or in

Motient‘s various operating licenses to support the position that an in—band terrestrial

f;fiobile service component to Motient‘s L—Band system is consistent with existing

Commission rules and policies.‘ 3

         First, the footnotes to the U.S. Table of Allocations cited by Motient are



‘‘Id. at 12. Motient already provides terrestrial services through ARDIS, which it acquired in 1998.
Motient provides that service pursuant to all of the relevant technical rules that the FCC established
through notice and comment rulemaking procedures. It is not apparent why Motient should not
similarly follow the Commission‘s rules for MSS.
** See In the Matter of Authorization and Use of Software Defined Radios, Notice of Proposed
Rulemaking, ET Docket No. 00—47 (December 7, 2000).
13       Pnap
   Application at 15.


specific to the Aeronautical Mobile Satellite (Route) Service. That service is reserved

specifically for "communications relating to safety and regularity of flights." * The

policy need for limited extension and supplement of satellite to aircraft

communications for safety and navigational purposes is both obvious and markedly

different from Motient‘s purely commercial goal of attracting more subscribers. 15

Furthermore, there are no parallel footnotes extending this supplemental authority to

land mobile or maritime MSS.

         Motient also argues that the Commission explored the notion of a dual

terrestrial/satellite service when it proposed a generic MSS system in 1985, through a

possible allocation of spectrum for the service adjacent to the cellular bands."" While

this is true, it does not support Motient‘s current proposal. First, the suggested

allocation would not have incorporated in—band dfial service, but rather, adjacent band

dual service. Second, the Commussion ultimately decided against this suggestion. In

fact, the 1985 MSS allocation proceeding is relevant to Motient‘s proposal chiefly

because the Commussion made clear from the outset that it did not believe that MSS

should compete with terrestrial mobile syétems, as Motient now proposes to do.""

         Finally, while Motient notes — correctly — that the Commission has expressed

some interest in the idea of a same—band satellite—terrestrial dual—operating system,

and more generally in promoting flexible spectrum use, ‘° the cases Motient cites are

not relevant to Motient‘s application. All of the dockets cited by Motient have either

been statements of the Commuission‘s general policy or else rulemaking proceedings



!* See 47 CFR § 87.5.
!* See, e. g., Application at 12, 13.
16 Application at 15.
*‘ See Amendment of Parts 2, 22 and 25 of the Commission‘s Rules to Allocate Spectrum for and
Establish Rules Pertaining to the Use of Radio Frequencies in the Land Mobile Satellite Service,
Notice of Proposed Rulemaking, Docket No. 84—1234, 50 Fed. Reg. 8149 (January 28, 1985) at
footnote 19.
18 Application at 10, footnote 14.


establishing initial service and licensing requirements open to any party interested in

supplying such service. By contrast, in this case Motient is attempting to introducs

new hybrid service by radically altering well established rules.

          In short, Motient‘s proposed operation of a terrestrial mobile service in the L—

Band is absolutely inconsistent with the existing rules. Motient has presented no

evidence to the contrary.


III.      No Good Cause Exists For Grant Of Motient‘s Waiver Request.

          As an alternative to finding that its proposed terrestrial service is consistent

with current rules, Motient also requests that the Commuission waive those rules to the

extent necessary to grant the proposal." The waivers of the L—Band service rules that

Motient requests, however, would disserve the public and cause major disruption and

hardship to the MSS industry. Motient has failed to provide sufficient justification to

warrant such waiver.

         A.      Motient‘s Proposal Would Jeopardize Critical L—Band Safety
                 Services.

         At the outset, it is extremely important to reiterate the fact that the L—Band

serves a special and important function in providing global maritime and aeronautical

safety services. As the Commuission is well aware, Inmarsat was created specifically

to provide such services. Successive ITU World Radiocommunication Conferences

allocated L—Band spectrum for MSS to be used where required for maritime and

acronautical safety—related services. Those obligations remain in effect regardless of

whatever commercial plan an MSS operator may choose to pursue. As discussed

below, Motient‘s proposal raises serious concerns with respect to the ability of

Inmarsat and other operators to fulfill their safety—related service obligations. The



* 1d. at 15.


Commission should not now effectively reallocate this spectrum, for the benefit of

one company, to terrestrial services and thereby jeopardize public safety both inside

and outside of the United States.

         B.       Authorization Of Terrestrial Mobile Services Would Harm
                  Existing And Future L—Band Satellite Operations.

         The Commussion is well aware of the chronic, long—standing shortage of

available L—Band spectrum. Motient itself has repeatedly told the Commussion that

the L—Band is extremely congested and contends that it has insufficient spectrum for

its current services."" Further, as Motient states several times, MSS operators must

use the available capacity as efficiently as possible."‘ Contrary to Motient‘s claim,

however, its proposed L—Band terrestrial service would detract from the efficient use

of the spectrum by other MSS operators.

                  1. Terrestrial Operations Would Significantly Damage Co—
                     Channel Satellite Frequency Reuse Capacity.

         One factor critical to determining the capacity available to MSS operators in

the L—Band is the extent of frequency reuse. By introducing additional interference

into the band, the Motient proposal has thé potential to reduce the level of reuse and

thereby the capacity available to MSS systems.

         Motient states that since the terrestrial fill—in service would use spectrum

coordinated for Motient‘s use, there would be no possibility of co—channel

interference except with respect to Motient‘s own satellites."" This assertion is




*See, e. g., Motient Services Inc.‘s Petitions to Deny Applications of Comsat Corporation, File No.
SAT—ITC—2000605—00103 (filed July 26, 2000); Comsat Corporation, File Nos. SES—LIC—20000609—
00944, 00946—00949 (filed August 4, 2000); Marinesat Communications Network d/b/a/ Stratos
Communications, File No. SES—LIC—2000426—00630 (filed July 7, 2000); Marinesat Communications
Network, File No. SES—MSC—2000426—00861 (filed July 7, 2000); Honeywell, Inc., File No. SES—LIC—
2000403—00534 (filed July 7, 2000); SITA Information Networking Computing Canada, Inc., File No.
SES—MSC—2000209—010201 (filed July 28, 2000); and Deere & Company, File No. SES—LIC—
20010112—00051 (filed March 9, 2001).
*! See, e.g., Application at 8.
22 Application at Appendix A, section 8.2.1.


incorrect because Motient ignores the fact that the L—Band MSS spectrum is not

strictly segmented between operators. Where possible, spectrum is reused on a

geographical basis. For example, some spectrum that is assigned to Motient and TMI

for use in North America is re—used by Inmarsat in South America. The Inmarsat

receiving satellite spot beams serving South America receive interference from

Motient or TMI terminals in the side lobes of the satellite antenna Reuse is feasible

because the aggregate interference from mobile earth stations is at acceptable levels.

The amount of additional interference that is acceptable depends on how close the

existing interference level is to the acceptable limit, and the actual increase depends

on the number of mobile terminals that are introduced, their power levels and the

average shielding between the terminals and the Inmarsat satellite. Motient‘s

terrestrial mobile terminals will cause additional ifiterference, however, and Inmarsat

believes that the total interference level will exceed acceptable levels.

         Thus, the proposed terrestrial fill—in use will degrade frequency reuse through

interference to MSS systems other than Motient‘s. But Motient‘s proposal would also

seriously degrade reuse within Motient‘s éwn system. Motient states that it can

prevent co—channel interference to its own satellites by satellite antenna discrimination

in combination with low levels of terrestrial mobile station effective isotropic radiated

power ("EIRP") toward the Motient satellites."" Even though the interference level

from a single mobile terminal may be low, however, the aggregate interference from a

large number of mobile stations could still degrade the reuse level of the Motient

system. A simple calculation is attached to demonstrate the principle."" The example,

which is not a worst case, calculates that no more than approximately thirty two




* 14. at footnote 1.
** See Attachment 1 hereto.


thousand terrestrial mobile stations could be introduced throughout the United States

and Canada without degrading the reuse.

        It may be technically possible that a limited number of mobile units could

operate in the band without any effect on the MSS. However, since MSS systems

operate at low radio link margins, the scale of any such use would necessarily be very

small. As Inmarsat‘s calculation shows, a very limited number of mobile stations

would degrade the frequency reuse in the band. The Motient application does not

specify how many mobile stations Motient anticipates but simply states that there will

be no interference to other systems and that no additional spectrum will be required.

This claim does not appear consistent with Motient‘s reference elsewhere in its

application to millions of potential customers for its proposed service. The

interference from millions of mobile terminals wéuld make MSS in the L—Band

completely impossible.

               2. Motient‘s Proposed Terrestrial Operations Will Adversely
                  Affect Sensitive Receivers Operating In Adjacent Frequency
                  Bands.

       In addition to the co—channel up-lifik interference problems described above,

Inmarsat believes that the power level of the transmissions from terrestrial base—

stations could block the down—link to MSS terminals operating near to the base

stations by overloading the sensitive receiving amplifiers of the MSS terminals.

Inmarsat users have experienced such blockage in the past from terrestrial mobile

transmissions in an adjacent band and manufacturers have been alerted to the problem

via terminal specifications. It is difficult, however, to design a sensitive receiver to

overcome the effects of high—powered terrestrial signals adjacent in frequency to the

wanted low—power satellite signal.


          Inmarsat provides transponders on the Inmarsat—3 and on future Inmarsat—4

satellites for the Radio Navigation Satellite Services at the GPS frequencies. Inmarsat

is concerned that the level of transmitted power from terrestrial base—stations also will

be sufficient to block reception of the satellite navigation signals in the adjacent GPS

band. This is because the receivers have only a limited amount offiltering to reduce

the adjacent band signal to a level that will not overload the receiving amplifi;:rs. It

is not a coincidence that the MSS down—link band is allocated adjacent to the RNSS

down—link band, since both services use sensitive, low—noise front—end amplifiers

which receive signals from satellites at similarly low levels. Motient ignores these

issues and instead confines itself to commenting on the protection of GPS signals

                                                     25
from out—of—band emissions of the base stations.

                  3. The Proposed Terrestrial Use Will Reduce The Amount Of
                     Spectrum Available For MSS Use.

          Both the degradation of co—channel up—link reuse and the adjacent channel

blocking of the down—link described above would affect the total availability of

spectrum for all MSS operators. If terrestrial use of the L—Band MSS spectrum

increases the interference levels to the extent that reuse between certain satellite

beams is no longer feasible, this will cause a serious reduction of the already limited

amount of spectrum available to MSS.

          Motient states that the operation of fill—in base stations will not require the

assignment of "any more spectrum.”26 Presumably this phrase refers to the amount of

spectrum that Motient has acquired through the multilateral coordination process. But

as shown above, Motient‘s use of L—Band spectrum for terrestrial service will

effectively block other operators from using that spectrum for MSS operations. Given



25 Application at Appendix A, Section 8.2.2.
°° Id. at 13.

                                               10


the shortages that already exist in this band and the increasing demands being placed

on this spectrum. the Commission should take no action that would reduce the

availability of this spectrum to satellite operators as Motient‘s proposal would do.

         Motient also states that there will be no need to subdivide the spectrum.*‘

Again this statement appears to be based on the assumption that satellite spectrum can

be reused by terrestrial systems without affecting the spectrum availability for the

satellite systems. As shown above, the introduction of terrestrial mobile stations will

degrade the reuse level among systems or within the Motient system. In this situation,

Motient would effectively need additional spectrum to support the terrestrial fill—in

service, whether this additional spectrum comes as a separate segment or not.

         C.       Motient‘s Proposal Would Allow The Terrestrial Tail To Wag The
                  Satellite Dog.                .

         As stated, Inmarsat strongly objects to any proposal that would reduce the

amount of spectrum available for MSS use. The Motient proposal has the potential of

doing just that if the proposed terrestrial network develops beyond a very limited fill—

in service towards a larger scale terrestrial mobile network. Inmarsat especially notes

Motient‘s statements such that its proposed new service "can be marketed to millions

of consumers in both rural and urban areas.""° Motient obviously believes that there

is a mass market for the proposed service. Certainly there is a mass market for

terrestrial mobile services. However, the terrestrial mobile mass market is served in

different frequency bands with the appropriate technology that allows substantial

frequency reuse. There is no spectrum to spare in the MSS allocations for this

service: MSS technology is being stretched to its limits to improve frequency re—use

as it is. Therefore, it should be used only for MSS systems. If Motient wishes, it can




*" Id at Appendix A, Section 2.3.
* Id at 13 (emphasis added).


                                            11


incorporate dual—band technology into its system, by combining the use of terrestrial

Mobile Service bands with MSS bands to produce a dual—band package.


IV.     Conclusion.

        Motient‘s application is a fairly candid statement that its previous spectrum

demands have been excessive and that it has been unable to generate much consumer

interest in its existing MSS service. Motient‘s proposal to introduce an in—band

terrestrial service also would suggest that it has more spectrum than it can use.

Motient claims in its application that it can operate both satellite and terrestrial units

on an interference—free basis but provides very little technical support for that claim.

       Motient‘s application represents a very bad solution to its technical and

financial problems. It clearly is in derogation of the Table of Frequency Allocations

in the Radio Regulations and current Commission L—Band policy. Motient‘s request

for waiver of these rules amounts to an effort to change the nature of its L—Band

service in a way that will make the scarcity of L—Band MSS allocations much worse

and jeopardize the provision of safety—related maritime and aeronautical services. In

addition, it could prevent operation of mobile earth stations in the MSS operating near

to any base—station, due to overloading of the front—end receiver by the high—level

signals coming from the base stations. The base stations will interfere with the

operation of nearby GPS receivers in the adjacent band in the same way.




                                             12


       Inmarsat continues to support efforts by members of the satellite community

to enhance the services they offer to the public. But Motient‘s proposed terrestrial L—

Band operations are unnecessary, would cause more harm than good and are not in

the public interest. For the reasons stated herein, the FCC should reject Motient‘s

request to provide terrestrial mobile service in the MSS bands.

                                                     Respectfully submitted,

                                                     INMARSAT VENTURES PLC




                                                        Kelly Cameron
                                                        Robert L. Galbreath
                                                        Powell Goldstein Frazer
                                                          & Murphy LLP
                                                       1001 Pennsylvania Ave., NW.
                                                        Sixth Floor
                                                        Washington, D.C. 20004
                                                       (202) 347—0066        ’

                                                     Its Attorneys
April 18, 2001




                                          13


                                   ATTACHMENT 1



1. Calculation of the maximum number of co—channel terrestrial users

        The following table illustrates how interference from terrestrial mobile

stations could cause unacceptable interference into an MSS system, even if the mobile

system was operating in a shielded environment (e.g. indoors) and in a geographically

separated area. The example is equally valid for inter— and intra—system interference.




C/(N+]T) requirement (Note 1)                           20      dB

C/(N+]I) without terrestrial mobile interference (2)    21      dB

Mobile earth station mode EIRP (3)(mobile to            5       dBW
satellite)                                          .

Mobile station mode EIRP (4)(mobile to base             0       dBW
station)

Satellite antenna discrimination                        20      dB

Average shielding (5)                                   15      dB

Number of co—frequency carriers from mobile             20
stations

C/I MS to MSS (6)                                       26.87 dB

C/(N+]1) total                                          20.02 dB




       Notes:

       (1) C/I requirement of the MSS carrier under consideration. This value

       includes thermal noise and other interference sources, including contributions

       due to reuse, either within the network or with another network, or both.

       (2) It is thus assumed that there is a 1 dB margin available for interference

       from terrestrial fill—in stations. It should be noted that the margin available for


        additional interference is typically very small in MSS systems and may be

        needed for other interference sources.

        (3) This value is taken from the MSV filing, Table 1—6 (p. 20). It can be noted

        that this is the maximum EIRP. For interference calculations the minimum

        EIRP should normally be used. Using the minimum EIRP would reduce the

        number of possible users.

        (4) Taken from the MSV filing, Table 2—1 (p. 30).

        (5) This level of shielding towards the GSO is considered a realistic average

        for a number of terminals operating indoors or in heavily cluttered

        environments.

        (6) This assumes that the propagation loss is equal for the wanted and

        interfering signal paths                     |

        Thus, in this example it would only be possible to introduce twenty radio

carriers from terrestrial mobile terminals to base stations, operating co—frequency with

the MSS carrier throughout the United States and Canada. It is considered that the

values chosen for the example are realistié; both better and worse cases could occur.

2.      Estimation of the possible scale of terrestrial fill—in service

        It is assumed that Motient would operate the terrestrial fill—in service in

spectrum assigned to Motient but not used for MSS in a given area. On this basis, it is

estimated that Motient would have approximately 6 MHz of spectrum available for

such use. Since the carrier bandwidth of the proposed terrestrial service is quoted as

200 kHz (Table 2—1 of Motient filing), there would thus be 30 carriers available.

Assuming each carrier can support six voice channels, there would be 180 voice

channels available. However, assuming that all the 30 carriers are made available in a

single terrestrial fill—in station cell, we calculate the traffic volume that can be


supported by this fill—in station‘, using the Erlang—B formula®. For a Grade of Service

of 1%, this total traffic volume is 160 Erlangs‘.

          Next, we estimate the traffic requirement of each user in the busy hour. As

Motient‘s proposed service appears to be similar to the planned third generation

mobile service (IMT—2000), we can take estimates from the ITU—R Report M.2023,

"Spectrum requirements for IMT—2000". The relevant parameters from Report

M.2023 are reproduced in the table below. Report M.2023 considers six "services"

and three "environments" for terrestrial IMT—2000. In the table below, three of these

services and two of the environments have been included, as these would seem to

correspond to those that would be supported by the proposed fill—in service.

                                      Busy hour call attempts  Call duration (sec)
                         Environment|    In—        Urban      In—        Urban
Service                               building   pedestrian building    pedestrian
Speech                                    3           0.8     180           120
Simple messaging                                0.6             0.3              3                 3
Switched data                                   0.2             0.2             156              156

          The traffic per user can be calculated for each combination of service and

environment by the formula (BHCA)*(Call duration)/360. The results are shown

below.

BH traffic per service (Erlangs)                In—building              Urban ped.
Speech                                             0.150                   0.027
Simple messaging                                      0.001                  0.000
Switched data                                         0.009                  0.009
                                     Total            0.159                  0.036



1 Using all the thirty carriers in one fill—in station means that it is not possible to implement another fill—
in station immediately adjacent to the first one. On the other hand, if several nearby fill—in stations are
required, only a sub—set of the 30 carriers could be made available to each. It is more likely that the
thirty available carriers would be used to create, for example, a four or seven—cell reuse pattern among
cells. The results in terms of the limit to the number of operating mobile terminals set by co—channel
interference to a satellite up—link carrier is similar. The first case would support a greater number of
users in total, since the trunking efficiency in each cell would be maximised.
* The Erlang—B formula is valid for circuit—switched traffic. Although some of Motient‘s traffic may be
packet switched, the Erlang—B formula can be used to get an estimate of the traffic volume.


          Thus, users in the "in—building" environment are expected to generate 0.159

Erlang in the busy hour and "urban pedestrian" users 0.036 Erlang. Taking an average

of 0.1 Erlang per user, a single fill—in cell could support 1600 users (160Erlangs

divided by 0.1Erlang per user). If the per user Erlang demand is larger, the number of

users must be reduced for a given grade of service.

         Since in this example 20 simultaneous co—frequency channels would be

acceptable, for the traffic levels assumed per user, these carriers would be able to

support (20*1600) = 32,000 users.

         Finally, it should be noted that the above example has assumed that all carriers

are used for voice telephony only. However, Motient plans to provide data services at

rates up to 160Kbits/sec.* Since a data transmission at that rate would require one

full carrier, the total number of users would be reauced accordingly.

3. Conclusion

         Through an example, and using non—worst case assumptions, it has been

shown that only a limited number of terrestrial mobile stations can be implemented

without causing degradation to the frequeficy re—use of MSS systems. For the example

used, a total of 20 carriers throughout the US and Canada would be possible, and the

maximum number of users that could be supported would be about 32,000.




° GoS of 1% is taken from ITU—R Report M.2023, which makes this assumption for terrestrial IMT—
2000.
* Application at 9.


                                                                                                           ©Goor
                         +44 171 T28 1778            INMARSAT
q7f/04 ‘01 TUB 16:02 FAX




                                                 CERTIFICATION

                    I hereby certify that I am the technically qualified person responsible for
             preparation of the engineering information contained in this pleading and its attachment,
             that I am familiar with Part 25 of the Commission‘s Rules, that I have reviewed the
             engineering information submitted in this pleading, and that it is complete and accurate to
             the best of my knowledge and belief.




            [7? &Ffl'[ 200|                                Jsigm_ture%_/»g—
            Date                                          Name: MyJonas Eneberg
                                                          Title: Mgnager, Spectrum


                                CERTIFICATE OF SERYVICE


       I, Mania Cabico, a secretary to the law firm of Powell, Goldstein, Frazer and Murphy
LLP, certify that copies of the attached Partial Petition to Deny of Inmarsat Ventures ple were
delivered April 18, 2001, via 1° class mail, postage prepaid, to the following parties:

Chairman Michael Powell *                    Commissioner Gloria Tristani *
Federal Communications Commission            Federal Communications Commussion
445 12"" Street, S.W.                        445 12"" Street, S.W.
Suite 8B201                                  Suite 8A204A
Washington, DC 20554                         Washington, DC 20554

Commissioner Susan Ness *                    Commussioner Harold Furchtgott—Roth *
Federal Communications Commission            Federal Communications Commission
445 12¢" Street, S.W.                        445 12"" Street, S.W.
Suite 8B115                                  Suite 8A¥A302
Washington, DC 20554                         Washington, DC 20554

Donald Abelson, Chief *                      Tom Tycz, Chief     *
International Bureau                         Satellite and Radiocommunication Division
Federal Communications Commission            International Bureau
445 12"" Street, S.W.                        Federal Communications Commission
Washington, D.C. 20554                       445 12"" Street, S.W.
                                             Washington, D.C. 20554

Thomas J. Sugrue, Chief *                    James Ball *
Wireless Telecommunications Bureau           International Bureau
Federal Communications Commission            Federal Communications Commission
445 12"" Street, S.W.                        445 12"" Street, S.W.
Washington, D.C. 20554                       Washington, D.C. 20554

Terrence E. Reideler *                       Herbert Zeiler *
International Bureau                         Wireless Telecommunications Bureau
Federal Communications Commission            Federal Communications Commission
445 12"" Street, S.W.                        445 12" Street, S.W.
Washington, D.C. 20554                       Washington, D.C. 20554


Bruce D. Jacobs                                  Lon C. Levin
David S. Konczal                                 Vice President and
Shaw Pittman                                        Regulatory Counsel
2300 N Street, N.W.                              Motient Services, Inc., and
Washington, D.C. 20037                             Mobile Satellite Ventures Subsidiary LLC
  Counsel for Motient Services, Inc.             10802 Parkridge Boulevard
  And Mobile Satellite Ventures Subsidiary LLC   Reston, VA 20191




                                         Maria Cabico
                                                         : Whke
* Via hand delivery



Document Created: 2012-01-13 15:03:15
Document Modified: 2012-01-13 15:03:15

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